Grate for zinc-furnaces.



J. D. JAMES. GRATE Fon zlNc FuRNAcE-s.

(Application led Sept. 11, 1899.) (No Model.) 2 Sheets-Sheet I,

No. 643,507'. Patented Feb. I3, |900.

l /NVE/vrof? Jaim/,2. James. n 4. By 7% A 77'0HNEYS Patented Feb. I3, 1900.

J D JAMES GRATE FOR ZINC FURNAGES.

(Appnmion mea sape. 11, 1899.1

y 2 Sheets-Sheet 2.

(No Mode.)

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.W www@ ATTORNEYS UNITED STATES `PAU-:Nr Fries.

JOHN D. JAMES, or PULASKI, VIRGINIA;

cRATE FOR zmo-FURNAC'S;

SPECIFICATION forming part of Letters Patent No. 643,507, dated February 13, 1900. Application filed September 11, 1899. Serial No. 730,146. (No model.)

To a/:ZZ whom, it Hurry concern,.-

Be it known that I, JOHN D. JAMES, of Pulaski, in the county of Pulaski and State of Virginia, have invented a new and useful Improvement in Grates for Zinc-Furnaces, of which the following is a specication.

In zinc-furnaces of the Belgian typethere is a long narrow fire-box built of masonry having a set of elevated grate-bars, above which, in the rire-chamber, there is arranged a series of transversely-placed retorts, while below the grate-bars there is an ash-pit of a vertical depth sufficient to admit workmen,

who every three hours or so are required to enter the ash-pits and with pokers or long iron tools break o the mass of clinkers adhering to the sides of the fire-box above the grate-bars, which clinkers rapidly form in the contracted portion of the furnace-chamber, which, on a level with the grate-bars in a zinc-furnace, is from ten to sixteen inches wide and from eight to twelve feet long. This work is performed while the tires are still burning. The clinkers are veryhard,'adhere with great tenacity to the sides of the furnace, and if not regularly removed at short intervals obstruct the fires and seriously affect the efficiency of the furnace. The elinkers are also difficult of access from below and the temperature in the ash-pit is ordinarily from 175O to 200. As the workmen have to enter the space the work is not only Very hard, but the effect of the heat upon the workmen is very severe.

My invention is designed to provide an improved form of grate-bar and method of operation which not only relieves the workmen from the influence of the heat, but alsoso changes the nature of the clinkers that they are no longer hard and vitreous, but are maintained as they are formed, in a spongy, frangi- Y section of the lower part of a zinc-furnace. Fig. 2 is a horizontal section just above the grate-bars; and Figs. 3, 4, and 5 are front, side, and plan views, respectively, of a system of spray-pipes which form a part of the grate of the furnace.

In the drawings, Figs. l and 2, A represents the wall of masonry forming the lower part of the zinc-furnace. lA is the fire-box, about ten inches wide at the bottom and twenty inches Wide at the top and about twelve feet long. At the bottom of this firebox is a grate of special construction, and below it is a chamber A2, forming the ash-pit, which is tall enough to admit the workmen who are required from time to time to clear off the clinkers above the grate. Now with such a proportion of fire-box having only a width of ten inches at the grate it will be seen that the mass of clinkers adhering to each side will soon obstruct the action of the fire.

My improved grate is formed as follows: At intervals of about four feet, more or less, there are cross-bars C C, whose ends are fixed in the masonry of the side walls. On the upper cross-bars the grate proper is laid, and the lower cross-bars C are simply rests upon which the upper end of the workmans long bar is supported in slicing the fire and breaking off the clinkers.

As shown, the grate is formedfof two longitudinally-arranged and solid grate-bars Bs B3, of square or other approved form of crosssection, and on either side adjacent to the walls and in parallel position are the iron pipes B B, one on each side and forming one of the grate-bars. These pipes are anchored down against displacement by long hookbolts b, having hooks on their upper ends that embrace the iron pipes B at suitable intervals, and screw-nuts on their lower ends which engage with the lower cross-bars C'. The pipes B B are continuous or run into each other at their back ends, and at their front ends the inlet end is turned up at B' and is provided with a valve b', by which the admission of water is regulated, while the other section B connects with a wastepipe or discharge-section B2, controlled by a valve b2. Throughout the length of the pipesections B B, that form grate-bars, there are IOO upon their upper surface numerous minute perforations forming jet-orifices a. When the Zinc-furnace is in operation, the valve l1' is opened and water is allowed to circulate through the pipe B and to issue in jets directed upwardly, striking the lower layer ot' coke, and blackening the fire at the lower level and also spraying and falling back on both the solid grate-bars B3 and the pipes B themselves. The valve b2, which is practically closed, is left alittle open, so that a little water will leak past the same and fall in a constant drip from the discharge-pipe B2. This is for the purpose of securing a circulation through the whole pipe and for the important purpose of forminga telltale which shall indicate always lthat the grate-bar pipes B B in the furnace are full, for if there is any stoppage in the flow through these pipes from any cause said pipes would quickly burn out. The issue of water from the jetorifices is maintained constantly, but is not a forcible spray, except just before the time when the clinkers are to be cleaned out, when the valve b is opened full, and a forcible spray is then thrown upward into the lower` level of the fire to still further cool it, so that the men may enter the ash-pit.

NowI am aware that it is not new to provide hollow grate-bars with jet-orifices on their upper sides which direct a blast of air or steam into the fire to promote combustion, and, on the other hand, I am aware that in some forms of furnace a water-pipe has been placed below the grate-bars with jet-orifices directed downward to sprinkle the floor of the ash-pit, and I do not claim any of these constructions or methods. My invention involves a distinctly new principle in physics,and also very important and new results in the particular kind of furnace to which it is applied, as follows:

The cooling of grate-bars by air or bya body of water circulating through them without issuing in jets acts only by conductivity and is very limited in extent. In my invention I take advantage of the rapid absorption of heat units involved in the change of aliquid to a gas which involves the principle of refrigeration involved in the evaporation of a volatile liquid in an ice-machine. Thus when the grate becomes suused on its upper 'side with water its rapid evaporation and conversion into vapor produces a far more rapid reduction of temperature than the mere circulation of a body of water through an imperforate pipe could, and, furthermore, the lower stratum of coke becomes bathed in this vapor and becomes blackened, so as to still further reduce the temperature. Not only is the heat thus greatly reduced and the work rendered more endurable to the workmen in cleaning out, but the clinkers themselves which accumulate and adhere to the walls just above the grate-bars are entirely changed in their physical structure, so that instead of being dense, hard, and vitreous they are spongy, friable, and easily disintegrated, and the severe labor of detaching them by hand is reduced to an unimportant and infrequent requirement. As a further advantage of my invention it has been found that while the temperature of the ash-pit and grate is so much reduced there is no loss of heat in the furnace above, for the aqueous vapor in being decomposed into its constituent gases in the furnace-chamber promotes the chemical union and intensifies the heat above, so as to give greater effectiveness to the fuel.

In carrying out my invention I do not limit myself to the particularform of devices shown,

as they may be changed in some respects without departing from my invention. Thus if the width of the fire-box should be made a little greater a third pipe B should properly be placed in alternation with the solid gratebars, whose longevity will thus be greatly increased.

One great advantage of my invention is the great saving in grate-bars. These as ordinarily arranged rapidly burn out, involving in some zinc plants as great an expenditure as one hundred dollars a month for gratebars alone. There is a great saving in fuel.

In describing my grate I show it in connection with a zinc-furnace, in which it has especial values; but I would have it understood that I do not confine it to a zine-furface, but may apply it to any and all kinds of furnaces-such as boiler-furnaces, puddling-furnaces, roasters, calciners, and copper-furnaces burning ordinary fuel.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. A grate for a furnace having a portion of its bars formed of hollow water-pipes and provided with perforations on their upper sides discharging upwardly into the fire-box, and valves regulating the fiow of water into and discharge from said pipe, substantially as and for the purpose described.

2. Agrateforafurnace havinghollowgrate-A bars with perforations on the upper surfaces discharging into the fire-box,- and means for' passing water through the same to form a constantly-suifused or superiicially-overflowing film of water on the surfaces of the grate-bars to reduce their temperature bydissipating the' heat units in surface evaporation substantially as and for the purpose described.

3. The combination with the zinc-furnace having a long and narrow fire-box and a deep ash-pit; of a grate interposed between the firebox and ash-pit and consisting of cross-bars supported at their ends by the walls of the furnace, and grate-bars arranged longitudinally on said cross-bars, part of said gratebars being constructed in the form of hollow perforated water-pipes, and valves for controlling the flow of water therethrough substantially as and for the purpose described.

4:. The combination withazinc-furnacehav inga long and narrow fire-box, and a deep ash- IOO IIO

pit; of a grate consisting of two sets of crossbars supported by walls of the furnace at their ends, a set of grate-bars arranged upon the upper set of cross-bars, part of which gratebars are made of hollow perforated waterpipes and provided with Valves for regulating the iow of water therethrough, and the lower set of cross-bars serving to support the cleaning-tools substantially as and for the purpose described.

5. The combination with a zinc-furnace having a long narrow fire-box and a deep ash-pit; of a grate consisting of two sets of cross-bars supported by the Walls of the furnace at their ends, a set of grate-bars arranged upon the upper set of cross-bars, hollow perforated water-pipes arranged in the plane of the gratebars, and hooked bolts hooking over said Wa ter-pipes, and anchored to the lower crosspurpose described.

6. The combination with a furnace-grate; of water-pipes arranged in the plane of the grate-bars between the grate-bars and side walls of the fire-box, said water-pipes having perforations on their upper sides to discharge upwardly into the fire-box to reduce the clinkers, and valves for controlling the ow of water through said pipes substantially as and for the purpose described.

In testimony whereof I have signed my name to this specication in the presence of two subscribing witnesses.

JOHN D. JAMES.

Witnesses:

E. O. CARTER, J oHN GEMMELL, Jr. 

